Draba heilii |
Draba oblongata |
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Canadian arctic Draba |
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Habit | Perennials; (densely cespitose); caudex few-branched (compact, with persistent, thickened leaves); not scapose. | Perennials; (cespitose); caudex branched (with persistent leaf remains); sometimes scapose. |
Stems | unbranched or branched distally, 0.3–0.7 dm, glabrous throughout or, rarely, pilose, trichomes simple and stalked, 2-rayed, 0.2–0.5 mm. |
unbranched, (0.2–)0.4–1.5(–1.9) dm, pubescent throughout, trichomes simple, 0.4–0.8 mm, and short-stalked, 4–10-rayed, 0.05–0.3 mm, (mostly branched distally). |
Basal leaves | (persistent, imbricate); rosulate; undifferentiated into blade and petiole (becoming indurate at base); blade linear-lanceolate, 0.5–0.8 cm × 1–1.5(–2) mm, margins entire, surfaces glabrous or, rarely, pilose with simple and stalked, 2-rayed trichomes, (margins ciliate with simple and, rarely, 2-rayed setiform trichomes, 0.5–1.3 mm, midvein prominent). |
rosulate; petiolate; petiole base and margin ciliate, (trichomes simple, 0.3–1 mm); blade oblanceolate to lanceolate, 0.4–1.5 cm × 1.5–5 mm, margins entire, surfaces pubescent with simple and stalked, 2- or 3-rayed trichomes, 0.4–1 mm, with short-stalked, 8–12-rayed, stellate ones, 0.1–0.2 mm. |
Cauline leaves | 6–8; sessile; blade linear-oblong, 0.5–0.8 cm × 1–2 mm (widest about base), margins entire, (ciliate). |
0–2; sessile; blade oblong to broadly ovate, margins entire, surfaces pubescent as basal. |
Racemes | 10–26-flowered, ebracteate, elongated in fruit; rachis not flexuous, usually glabrous, rarely pubescent, (trichomes non-crisped, simple and 2-rayed). |
5–13(–18)-flowered, ebracteate, elongated in fruit; rachis not flexuous, pubescent as stem distally. |
Flowers | sepals ovate, 1.7–2.7 mm, usually glabrous, rarely pilose, (trichomes simple); petals yellow, oblong-oblanceolate, 4–6 × 1.5–2 mm; anthers oblong, 0.5–0.6 mm. |
sepals ovate, 2–3 mm, pubescent, (trichomes simple and short-stalked, mostly 2-rayed); petals white, spatulate to obovate, 3.5–5 × 1.5–2.5 mm; anthers ovate, 0.2–0.3 mm. |
Fruiting pedicels | ascending, straight, 3–5(–7) mm, usually glabrous, rarely pilose, (trichomes simple and 2-rayed, stalked). |
divaricate to ascending, straight, 2–6(–8) mm, pubescent as rachis. |
Fruits | narrowly lanceolate, twisted 1/2 turn or plane, flattened, 7–10 × 1.3–1.6 mm; valves glabrous; ovules 16–20 per ovary; style 0.7–1.3 mm. |
elliptic to oblong, plane, slightly flattened, 4–8(–9.5) × 2–3(–4) mm; valves pubescent, trichomes short-stalked, (2–)5–12-rayed, 0.05–3 mm; ovules 24–36 per ovary; style 0.2–0.8 mm (stigma considerably wider than style, often appearing 2-lobed). |
Seeds | ovoid, 1 × 0.6 mm. |
ovate, 0.7–1 × 0.5–0.6 mm. |
2n | = 64. |
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Draba heilii |
Draba oblongata |
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Phenology | Flowering Jun–Jul. | Flowering Jun–Jul. |
Habitat | Alpine tundra | Ridges and hillsides, sand and gravel flood plains, swales, tundra |
Elevation | ca. 3700 m (ca. 12100 ft) | 0-400 m (0-1300 ft) |
Distribution |
NM |
AK; NT; NU; Greenland; e Asia (Russian Far East, Siberia) |
Discussion | Draba heilii is restricted to Mora and Rio Arriba counties. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Plants of Draba oblongata are occasionally misidentified as decaploid (2n = 80) D. arctica, but the former is readily separated by a preponderance of simple (versus stellate) trichomes on both leaf blade surfaces. Draba oblongata is sometimes confused with D. micropetala, but the latter has pale yellow (versus white) flowers, fruits pubescent with simple and spurred (versus (2–)5–12-rayed) trichomes, and stigmas as wide as (versus much wider than) the style. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 311. | FNA vol. 7, p. 323. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | D. arctica subsp. groenlandica, D. cinerea subsp. groenlandica, D. groenlandica | |
Name authority | Al-Shehbaz: Harvard Pap. Bot. 14: 83, fig. 1. (2009) | R. Brown ex de Candolle: Syst. Nat. 2: 342. (1821) |
Web links |